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David Van Couvering

David Van Couvering has spent his engineering career crossing the bridge between databases and the middle tier world of application servers, Java and distributed systems. He was the original architect for the Sybase J2EE application server and for the first release of the clustered Sun Java Application Server Enterprise Edition. Currently he is involved in database technology at Sun, working with the Clustra team in Norway, and is a committer to the Apache Derby open source database. He lives in Berkeley and his favorite pasttimes are coding, meditation and spending time with his daughter.


davidvc's blog

Internet content by reference, not by value

Posted by davidvc on May 9, 2008 at 9:07 AM PDT

Note: if we had DRY working for blogs, then I could have just embedded the content from
my other blog
and not have had to enter things in twice. Posting a link is not the same as having the content immediately available, which is why I decided to just copy the blog.

You can help with NetBeans database tooling

Posted by davidvc on October 18, 2007 at 2:46 PM PDT


I know this isn't my main blog page any more (I'm hanging out at,
but I wanted to reach out to you all and get your input.

We are looking at what we want to do next with database toolin

Moving to new digs

Posted by davidvc on June 27, 2007 at 1:19 AM PDT

I've decided to move my blog to a new location. You can now find me at

Why am I making the move? Well, this was a hard decision.

Replication? In Java DB? Wow.

Posted by davidvc on June 22, 2007 at 1:46 PM PDT

Open source continues to amaze me. For so many years, I have worked on projects where customers would clamor for features, and we just didn't have enough time in the day or people to get them all built. We would say "yeah, that sounds cool" but with all the other things on our plate, when would we ever get to it?

Well, in open source, it's a whole different ball game.

Derby 10.3 Beta Available

Posted by davidvc on June 22, 2007 at 11:02 AM PDT

Derby 10.3 beta
is available for testing
. If you are using Derby/Java DB, you should try your local tests with this beta and make sure everything's working for you.

This page describes what's in this release.

Spam Vegetable Strudel

Posted by davidvc on June 21, 2007 at 5:10 PM PDT

I noticed today that I had 754 messages in my Spam folder in Gmail.

I decided to open the folder, and GMail had decided to place the following sponsored link at the top of the folder:

"Spam Vegetable Strudel - Bake 20 minutes or until golden, serve with soy sauce"

I just did a refresh, and now it says "Spam Imperial Tortilla Sandwiches - To serve, cut each roll in half"

Yum, yu

Legal Blogging

Posted by davidvc on June 20, 2007 at 4:47 PM PDT

I am a techie, and generally am not interested in the legal world. That changed a bit when I got into open source, where just to be able to contribute code you have to have some pretty solid understanding of open source licenses.

I wasn't sure what to think when I heard Sun's general counsel, Mike Dillon, had started a blog.

Java DB Authorization using GRANT and REVOKE

Posted by davidvc on June 17, 2007 at 7:23 PM PDT

The default behavior of Java DB is that you have two level of access control: full access and read-only. Again, this is I believe due to the legacy of Cloudscape being originally an embedded-only database.

No More Java DB Password in The Clear

Posted by davidvc on June 15, 2007 at 4:21 PM PDT

As I mentioned in my previous blog, Java DB's legacy is in the embedded world, where there is no such thing as sending the password over the wire.

But when you introduce the network client, this becomes an issue. And sending users and passwords in the clear is just not acceptable.

Authentication and Authorization with the Java DB Network Server

Posted by davidvc on June 15, 2007 at 3:44 PM PDT

The original Cloudscape was built as an embedded-only database -- that is, it could only run inside the VM of another application. It did not have a client/server mode. That was added later.

In some areas, Java DB continues to carry have this embedded "legacy" with it. One particular area you should be aware of is authentication and authorization.